Ocean Acidification: Influence of Ocean Acidification on Biotic Controls of DMS Emissions

海洋酸化：海洋酸化对 DMS 排放生物控制的影响

• 批准号: 1316133
• 负责人: Stephen Archer
• 金额: $ 129.05万
• 依托单位: Bigelow Laboratory for Ocean Sciences
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-10-01 至 2018-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1316133&HistoricalAwards=false
• 关键词: Ocean; Acidification; Influence; Biotic; Controls

To date, investigations into the biogeochemical consequences of predicted increases in pCO2 and reduced pH in the oceans (ocean acidification, OA) over the next century have largely focused on the production and fate of carbon. Considerably less is known about how OA will influence other biogeochemical cycles or the exchange of reactive trace gases between ocean and atmosphere. Variations in trace gas exchange will alter atmospheric chemistry, including aerosol formation and growth, and potentially feedback on climate change. In this project, a research team at the Bigelow Laboratory for Ocean Sciences will study the influence of OA on the biological processes that govern the concentrations and hence emission, of dimethyl sulfide (DMS) in the surface oceans. The team will study OA effects on the DMS-cycle in three natural-water mesocosm experiments designed to encompass natural community responses to predicted changes in pCO2 of varying degrees. They will exploit the opportunity to participate in a major experiment in sub-tropical oceanic waters involving the deployment of nine large scale (~60 m3) free floating, pelagic mesocosms, as part of the German-funded BIOACID Program. Two replicate experiments conducted using the new mesocosm facilities at Bigelow will further expand the environmental range of DMS-OA studies. Through a combination of standard analytical approaches, recently developed cutting-edge tracer approaches to determine process rates, as well as the underlying organism diversity and genetic response of microbes involved with biogenic sulfur cycling, they will determine how altered pH influences key biological pathways governing DMS concentrations and the organisms responsible during the experiments. Broader Impacts: The information generated will be used to inform on-going development of global ocean-atmosphere coupled models, able to examine the influence of ocean acidification on climate change. The information will also be used to further develop physiology-based mechanistic approaches to biogeochemical ecosystem models. A Postdoctoral Research Scientist will be trained in the experimental approaches, will gain modeling experience by working with European scientists, and will develop international and US collaborations, with a common aim to increase our understanding of ocean acidification on ecosystem function. Four undergraduates, two interns and two REU-students, will gain valuable experience by participating in the Bigelow experiments. An additional undergraduate with a mathematical background will be mentored in and participate in the interpretation and modeling aspects. Extensive outreach to K-12 students and teachers as well as the general public will be pursued as part of established Bigelow programs in which all PIs will participate (BLOOM, Cafe Scientifique). Joint programs with Colby College (Changing Oceans semester) and Island Institute will reach undergraduates and Maine island K-8 schools, respectively.

迄今为止，对预测下个世纪海洋中 pCO2 增加和 pH 值降低（海洋酸化，OA）的生物地球化学后果的研究主要集中在碳的产生和归宿上。关于 OA 将如何影响其他生物地球化学循环或海洋和大气之间反应性微量气体的交换，人们知之甚少。微量气体交换的变化将改变大气化学，包括气溶胶的形成和增长，以及对气候变化的潜在反馈。在该项目中，毕格罗海洋科学实验室的一个研究小组将研究 OA 对控制海洋表层二甲硫醚 (DMS) 浓度和排放的生物过程的影响。 该团队将在三个天然水中生态实验中研究 OA 对 DMS 循环的影响，这些实验旨在涵盖自然群落对不同程度的 pCO2 预测变化的反应。作为德国资助的 BIOACID 计划的一部分，他们将利用这个机会参与亚热带海洋水域的一项重大实验，其中涉及部署九个大型（约 60 立方米）自由漂浮的中上层环境。使用毕格罗新的中宇宙设施进行的两项重复实验将进一步扩大 DMS-OA 研究的环境范围。通过结合标准分析方法、最近开发的尖端示踪剂方法来确定过程速率，以及参与生物硫循环的微生物的潜在生物多样性和遗传反应，他们将确定 pH 值的变化如何影响控制 DMS 的关键生物途径浓度和实验过程中负责的生物体。更广泛的影响：生成的信息将用于为全球海洋-大气耦合模型的持续开发提供信息，从而能够研究海洋酸化对气候变化的影响。这些信息还将用于进一步开发基于生理学的生物地球化学生态系统模型的机械方法。博士后研究科学家将接受实验方法方面的培训，通过与欧洲科学家合作获得建模经验，并将开展国际和美国合作，其共同目标是增进我们对海洋酸化对生态系统功能影响的理解。四名本科生、两名实习生和两名 REU 学生将通过参与毕格罗实验获得宝贵的经验。另外一名具有数学背景的本科生将接受指导并参与解释和建模方面的工作。作为毕格罗既定项目的一部分，所有 PI 都将参与其中（BLOOM、Cafe Scientifique），将针对 K-12 学生和教师以及公众进行广泛的宣传。与科尔比学院（改变海洋学期）和岛屿学院的联合项目将分别面向本科生和缅因岛 K-8 学校。